| 1. |
- Feroci, M., et al.
(författare)
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The large observatory for x-ray timing
- 2014
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 9780819496126
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Konferensbidrag (refereegranskat)abstract
- The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final downselection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the strong gravitational field in the innermost regions of accretion flows close to black holes and neutron stars, and the supranuclear densities in the interior of neutron stars. The science payload is based on a Large Area Detector (LAD, 10 m2 effective area, 2-30 keV, 240 eV spectral resolution, 1° collimated field of view) and a Wide Field Monitor (WFM, 2-50 keV, 4 steradian field of view, 1 arcmin source location accuracy, 300 eV spectral resolution). The WFM is equipped with an on-board system for bright events (e.g. GRB) localization. The trigger time and position of these events are broadcast to the ground within 30 s from discovery. In this paper we present the status of the mission at the end of its Phase A study.
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| 2. |
- Feroci, M., et al.
(författare)
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LOFT - The large observatory for x-ray timing
- 2012
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE - International Society for Optical Engineering. - 9780819491442 ; , s. 84432D-
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Konferensbidrag (refereegranskat)abstract
- The LOFT mission concept is one of four candidates selected by ESA for the M3 launch opportunity as Medium Size missions of the Cosmic Vision programme. The launch window is currently planned for between 2022 and 2024. LOFT is designed to exploit the diagnostics of rapid X-ray flux and spectral variability that directly probe the motion of matter down to distances very close to black holes and neutron stars, as well as the physical state of ultradense matter. These primary science goals will be addressed by a payload composed of a Large Area Detector (LAD) and a Wide Field Monitor (WFM). The LAD is a collimated (<1 degree field of view) experiment operating in the energy range 2-50 keV, with a 10 m2 peak effective area and an energy resolution of 260 eV at 6 keV. The WFM will operate in the same energy range as the LAD, enabling simultaneous monitoring of a few-steradian wide field of view, with an angular resolution of <5 arcmin. The LAD and WFM experiments will allow us to investigate variability from submillisecond QPO's to yearlong transient outbursts. In this paper we report the current status of the project.
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| 3. |
- Dunn, R. J. H., et al.
(författare)
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GLOBAL CLIMATE : State of the Climate in 2020
- 2021
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Ingår i: Bulletin of the American Meteorological Society. - : American Meteorological Society. - 0003-0007 .- 1520-0477. ; 102:8
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Bodin, Fernando, 1991, et al.
(författare)
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The Association of Cigarette Smoking With High-Frequency Heart Rate Variability: An Ecological Momentary Assessment Study
- 2017
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Ingår i: Psychosomatic Medicine. - : Ovid Technologies (Wolters Kluwer Health). - 0033-3174 .- 1534-7796. ; 79:9, s. 1045-1050
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Tidskriftsartikel (refereegranskat)abstract
- Objective Evidence from both laboratory and observational studies suggests that acute and chronic smoking leads to reduced high-frequency heart rate variability (HF-HRV), a measure of cardiac vagal regulation. We used ecological momentary assessment (EMA) to study the effect of smoking on concurrent HF-HRV in a trial measuring the effects of hostility reduction and compared 24-hour HF-HRV in smokers and nonsmokers. Method Ambulatory electrocardiogram data were collected before randomization from 149 healthy individuals with high hostility levels (20-45 years, body mass index 32 kg/m(2)) and paired with concurrent EMA ratings of smoking and physical position during waking hours. A multilevel mixed model was estimated associating ln(HF-HRV) from smoking status (between-person factor) and person-centered momentary smoking (within-person factor, treated as a random effect), adjusting for momentary physical position, medication use, and consumption of alcohol and caffeine. Results Thirty-five smokers and 114 nonsmokers provided both EMA and HF-HRV data. Within smokers, ln HF-HRV was reduced by 0.31 millisecond(2) (p = .04) when participants reported having recently smoked cigarettes, compared with when they had not. The 24-hour HF-HRV was significantly lower in smokers (M [SD] = 5.24 [0.14] milliseconds(2)) than nonsmokers (5.63 0.07 milliseconds(2), p = .01). Conclusions In healthy smokers with high hostility levels used as their own controls during daily living, smoking acutely reduced HF-HRV. HF-HRV was also reduced in smokers as compared with nonsmokers. Although limited by a small sample of individuals with high hostility levels, these findings nonetheless provide additional evidence that cardiac vagal regulation is lowered by cigarette smoking, which may be one of the numerous pathophysiological effects of smoking.
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| 5. |
- Perri, M, et al.
(författare)
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Precarious work on the rise
- 2024
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Ingår i: BMC public health. - 1471-2458. ; 24:1, s. 2074-
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Tidskriftsartikel (refereegranskat)
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| 6. |
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| 7. |
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| 8. |
- Bodin, Örjan, et al.
(författare)
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Improving network approaches to the study of complex social–ecological interdependencies
- 2019
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Ingår i: Nature Sustainability. - : Springer Science and Business Media LLC. - 2398-9629. ; 2:7, s. 551-559
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Tidskriftsartikel (refereegranskat)abstract
- Achieving effective, sustainable environmental governance requires a better understanding of the causes and consequences of the complex patterns of interdependencies connecting people and ecosystems within and across scales. Network approaches for conceptualizing and analysing these interdependencies offer one promising solution. Here, we present two advances we argue are needed to further this area of research: (i) a typology of causal assumptions explicating the causal aims of any given network-centric study of social–ecological interdependencies; (ii) unifying research design considerations that facilitate conceptualizing exactly what is interdependent, through what types of relationships and in relation to what kinds of environmental problems. The latter builds on the appreciation that many environmental problems draw from a set of core challenges that re-occur across contexts. We demonstrate how these advances combine into a comparative heuristic that facilitates leveraging case-specific findings of social–ecological interdependencies to generalizable, yet context-sensitive, theories based on explicit assumptions of causal relationships.
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| 9. |
- Gustavsson, P., et al.
(författare)
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Time trends in occupational exposure to chemicals in Sweden: proportion exposed, distribution across demographic and labor market strata, and exposure levels
- 2022
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Ingår i: Scandinavian Journal of Work, Environment and Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 48:6, s. 479-489
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Tidskriftsartikel (refereegranskat)abstract
- Objective This study investigated time trends in occupational exposure to various chemicals in Sweden and the distribution across demographic and labor market sectors. Methods Exposure to six chemicals was investigated from 1980 to 2013 by application of a job exposure matrix to national population registers. Respirable crystalline silica (RCS), diesel engine exhaust, welding fumes, wood dust, chlorinated hydrocarbon solvents, and lead were selected to represent different groups of chemicals. Trends in exposure prevalence were investigated by linear regression and compared to the occupationally active popula-tion. Confidence intervals for the rate of change over time were obtained by bootstrapping. Results The proportion of workers born outside the Nordic countries increased over time in those exposed to RCS, diesel exhaust and wood dust. There was a shift of exposed jobs to small companies (<50 employees), especially for RCS, welding fumes, wood dust, and chlorinated hydrocarbon solvents. For RCS and welding fumes, there was a marked drop in exposure levels from 1980 to 1990 but small changes thereafter. Exposure to lead diminished, both in terms of prevalence and intensity. Conclusions Over time, several exposures tended to shift to small companies, the construction sector, and migrant workers, all factors being indicative of less well-controlled working conditions. Occupational exposure to chlorinated organic solvents and lead diminished, while exposure levels to RCS and welding fumes have changed little since 1990. In view of the serious and well-established negative health effects, increased efforts to reduce exposure to RCS and welding fumes are needed.
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| 10. |
- Janssen, M A, et al.
(författare)
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Toward a network perspective of the study of resilience in social-ecological systems
- 2006
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Ingår i: Ecology and Society. - : Resilience Alliance, Inc.. - 1708-3087. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Formal models used to study the resilience of social-ecological systems have not explicitly included important structural characteristics of this type of system. In this paper, we propose a network perspective for social-ecological systems that enables us to better focus on the structure of interactions between identifiable components of the system. This network perspective might be useful for developing formal models and comparing case studies of social-ecological systems. Based on an analysis of the case studies in this special issue, we identify three types of social-ecological networks: ( 1) ecosystems that are connected by people through flows of information or materials, ( 2) ecosystem networks that are disconnected and fragmented by the actions of people, and ( 3) artificial ecological networks created by people, such as irrigation systems. Each of these three archytypal social-ecological networks faces different problems that influence its resilience as it responds to the addition or removal of connections that affect its coordination or the diffusion of system attributes such as information or disease.
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| 11. |
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| 13. |
- Porto, G., et al.
(författare)
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Thermodynamic and thermoelastic properties of hypostoichiometric MOX fuels with molecular dynamics simulations
- 2024
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Ingår i: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115 .- 1873-4820. ; 598
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Tidskriftsartikel (refereegranskat)abstract
- Employing the Cooper-Rushton-Grimes (CRG) interatomic empirical potential with new parameters for U3+ interactions in U1-y,PuyO2-x, classical Molecular Dynamics simulations were carried out for the first time to compute the enthalpy, the lattice parameter, the elastic constants and derived properties of hypostoichiometric U1-y,PuyO2-x compounds (with y in the range 0-1, x between 1.92-2.0, and from 1000 K to melting points). As hypostoichiometry results from adding oxygen vacancies to U1-y,PuyO2, this study investigates how oxygen vacancies affect the thermodynamic and thermomechanical properties of MOX compounds. The most pronounced effect appears at high temperatures, where the so-called Bredig transition occurs. We observed that the effects of this transition on the properties are softened by the presence of oxygen vacancies. The analytical law of the heat capacity for stoichiometric mixed-oxide fuels U1-y,PuyO2 developed by Bathellier et al. [9] was modified by introducing the deviation from stoichiometry as a variable. It was fitted on Molecular Dynamics data of heat capacity and linear thermal expansion coefficient and a good agreement was found. To model the thermal evolution of mechanical properties up to the melting point, a new law was developed. The laws may be used in Fuel Performance Codes.
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| 14. |
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| 15. |
- Alexander, Steven M., et al.
(författare)
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Social ties explain catch portfolios of small-scale fishers in the Caribbean
- 2020
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Ingår i: Fish and Fisheries. - : Wiley. - 1467-2960 .- 1467-2979. ; 21:1, s. 120-131
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Tidskriftsartikel (refereegranskat)abstract
- Small-scale fisheries often involve weak management regimes with limited top-down enforcement of rules and minimal support from legal institutions, making them useful model systems for investigating the role of social influence in determining economic and environmental outcomes. In such regimes, interpersonal relationships are expected to have a strong effect on a fisher's catch portfolio, the set of fish species targeted by an individual fisher. Here, we test three competing hypotheses about social influence using belief propagation network models and show that a peer-to-peer information-sharing social network is key to explaining catch portfolios at a small-scale fishery in Jamaica. We find that experience dictates the direction of influence among fishers in the social network, with older fishers and information brokers having distinct roles in shaping catch patterns for large- and small-sized fish species, respectively. These findings highlight concrete opportunities for harnessing social networks in natural resource management. Our new approach to modelling social influence is applicable to many social-ecological systems with minimal legal and institutional support or those that rely heavily on bottom-up participatory processes.
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| 16. |
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| 21. |
- Bodin, P., et al.
(författare)
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Accounting for interannual variability in agricultural intensification : The potential of crop selection in Sub-Saharan Africa
- 2016
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X. ; 148, s. 159-168
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Tidskriftsartikel (refereegranskat)abstract
- Providing sufficient food for a growing global population is one of the fundamental global challenges today. Crop production needs not only to be increased, but also remain stable over the years, in order to limit the vulnerability of producers and consumers to inter-annual weather variability, especially in areas of the world where the food consumed is mainly produced locally (e.g. Sub Saharan Africa (SSA)). For subsistence agriculture, stable yields form a crucial contribution to food security. At a regional to global scale dynamical crop models can be used to study the impact of future changes in climate on food production. However, simulations of future crop production, for instance in response to climate change, often do not take into account either changes in the sown areas of crops or yield interannual variability. Here, we explore the response of simulated crop production to assumptions of crop selection, also taking into account interannual variability in yields and considering the response of agricultural productivity to climate change. We apply the dynamic global vegetation model LPJ-GUESS, which is designed to simulate yield over large regions under a changing environment. Model output provides the basis for selecting the relative fractions of sown areas of a range of crops, either by selecting the highest yielding crop, or by using an optimization approach in which crop production is maximized while the standard deviation in crop production is kept at below current levels. Maximizing simulated crop production for current climate while keeping interannual variability in crop production constant at today's level generates rather similar simulated geographical distributions of crops compared to observations. Even so, the optimization results suggest that it is possible to increase crop production regionally by adjusting crop selection, both for current and future climate, assuming the same cropland cover as today. For future climates modelled production increase is > 25% in more than 15% of the grid cells. For a small number of grid cells it is possible to both increase crop production while at the same time decreasing its interannual variability. Selecting the highest yielding crop for any location will lead to a large potential increase in mean food production, but at the cost of a very large increase in variability.
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| 22. |
- Bodin, Per, et al.
(författare)
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Comparing the performance of different stomatal conductance models using modelled and measured plant carbon isotope ratios (δ(13) C): implications for assessing physiological forcing
- 2013
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013. ; 19:6, s. 1709-1719
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Tidskriftsartikel (refereegranskat)abstract
- Accurate modelling of long-term changes in plant stomatal functioning is vital to global climate change studies because changes in evapotranspiration influence temperature via physiological forcing of the climate. Various stomatal models are included in land surface schemes, but their robustness over longer timescales is difficult to validate. We compare the performance of three stomatal models, varying in their degree of complexity, and coupled to a land surface model. This is done by simulating the carbon isotope ratio of tree leaves (δ(13) Cleaf ) over a period of 53 years, and comparing the results with carbon isotope ratios obtained from tree rings (δ(13) Cstem ) measured at six sites in northern Europe. All three stomatal models fail to capture the observed inter-annual variability in the measured δ(13) Cstem time series. However, the Soil-Plant-Atmosphere (SPA) model performs significantly better than the Ball-Berry (BB) or COX models when tested for goodness of fit against measured δ(13) Cstem . The δ(13) Cleaf time series simulated using the SPA model are significantly positively correlated (p < 0.05) with measured results over the full time period tested, at all six sites. The SPA model underestimates inter-annual variability measured in δ(13) Cstem , but is no worse than the BB model and significantly better than the COX model. The inability of current models to adequately replicate changes in stomatal response to rising levels of CO2 concentrations, and thus to quantify the associated physiological forcing, warrants further investigation. © 2013 Blackwell Publishing Ltd.
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| 23. |
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| 25. |
- Enqvist, Johan P., et al.
(författare)
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Are bottom-up approaches good for promoting social-ecological fit in urban landscapes?
- 2020
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Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 49:1, s. 49-61
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Tidskriftsartikel (refereegranskat)abstract
- Bottom-up approaches are often presented as a remedy to environmental governance problems caused by poorly aligned social institutions and fragmented ecosystems. However, there is a lack of empirical evidence demonstrating how such social-ecological fit might emerge and help achieve desirable outcomes. This paper combines quantitative social-ecological network analysis with interviews to investigate whether bottom-up approaches in lake governance improve the fit. We study groups of residents seeking to improve management of a network of lakes in Bengaluru, India. Results show that 23 'lake groups' collaborate in a way that aligns with how lakes are hydrologically connected, thus strengthening the social-ecological fit. Three groups founded around 2010 have mobilized support from municipal officers and introduced an ecosystem-based approach to lake management that recognizes their ecological functions and dependence on, the broader hydrological network. These groups have also changed how other lake groups operate: groups founded after 2010 are more collaborative and more prone to contribute to social-ecological fit compared to the older lake groups. This paper demonstrates the utility of a theoretically informed method for examining the impact of bottom-up approaches, which, we argue, is important for a more informed perspective on their relevance and potential contribution to urban environmental governance.
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